Which of the following statements are correct ?
Light reaction occurs in stroma.
Light reaction occurs in grana.
Dark reaction occurs in stroma.
Dark reaction occurs in grana.
Choose the correct option.

Options

A. I and II
B. II and IV
C. III and IV
D. II and III

Answer

To determine which statements are correct regarding the light and dark reactions of photosynthesis, let's analyze each statement step by step.

### Step-by-Step Solution:

1. **Understanding Light Reactions**:
- Light reactions are the first stage of photosynthesis and require light to occur.
- They take place in the thylakoid membranes of the chloroplasts.
- The stacks of thylakoids are called grana.

**Conclusion**: The statement "Light reaction occurs in grana" is correct.

2. **Analyzing the First Statement**:
- The statement "Light reaction occurs in stroma" is incorrect because light reactions occur in the thylakoids (grana), not in the stroma.

3. **Understanding Dark Reactions**:
- Dark reactions, also known as the Calvin cycle, do not require light directly but use the products of light reactions (ATP and NADPH).
- Dark reactions occur in the stroma of the chloroplasts.

**Conclusion**: The statement "Dark reaction occurs in stroma" is correct.

4. **Analyzing the Fourth Statement**:
- The statement "Dark reaction occurs in grana" is incorrect because dark reactions occur in the stroma, not in the grana.

### Summary of Correct Statements:
- Correct Statements:
- "Light reaction occurs in grana." (Statement 2)
- "Dark reaction occurs in stroma." (Statement 3)

### Final Answer:
The correct options are:
- Statement 2: Light reaction occurs in grana.
- Statement 3: Dark reaction occurs in stroma.

Thus, the correct answer is option D (Statements 2 and 3 are correct).

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